Uptake and depuration of 131I by the edible periwinkle Littorina littorea: uptake from labelled seaweed ( Chondrus crispus)

Abstract

Uptake and depuration experiments of 131I from labelled seaweed ( Chondrus crispus) by the edible periwinkle Littorina littorea have been performed. Radioiodine concentrations in winkles during uptake followed first-order kinetics with an uptake half-time of 1 day, and a calculated equilibrium concentration ( C ∞ ) of 21 000 Bq kg −1 resulting in a transfer factor of 0.07 with respect to the labelled seaweed used as food. For depuration, a biphasic sequence with biological half-lives of 1 and 24 days was determined. The results suggest that in general, iodine turnover in periwinkles is slower than observed for other molluscs (monophasic biological half-lives in the order of 2–3 days). Both environmental media, food and seawater, can be significant sources of radioiodine for the winkle.